August 20, 1987
BCAB #928
Re: Curved Stair, Article 9.8.5.2.
With reference to your letter of June 10, 1987, regarding curved stairs within a dwelling unit.
The drawing submitted showed a staircase turning through 180, by means of four tapered treads. These treads do not converge to a point, so Article 9.8.5.3. is not applicable.
You state that the tapered treads have a minimum run of 150 mm, an average run of at least 200 mm, and a rise of 7.5 in (191 mm). On the basis of these dimensions they would comply with the provisions of Article 9.8.5.2. as curved stairs.
J.C. Currie, Chair